氢化物－原子吸收光谱法测定人发中的微量硒

研究了氢化物发生器与原子吸收分光光度计联用，测定人发中的微量硒．样品前处理选用ＨＮＯ＿３－ＨＣＩＯ＿４－Ｈ＿２Ｏ＿２湿法消解。在所选定硒的最佳测试条件下，测得了部分儿童发硒的数据。同时还确定了锌、铁、镁、锰、钙、铜、铅７种元素对测定硒的影响。     

甲醇催化脱氢制甲酸甲酯反应中Cu－ZrO_2／SiO_2催化剂的特性

考察了常压和２７０℃时甲醇催化脱氢制取甲酸甲酯反应中Ｃｕ－ＺｒＯ２／Ｓｉ４和Ｃｕ－ＺｒＯ／ＳｉＯ４催化剂的活性和选择性，并对催化剂进行了表征．结果表明，Ｃｕ－ＺｒＯ／ＳｉＯ４催化剂的反应性能优于Ｃｕ－ＺｒＯ／ＳｉＯ２催化剂．Ｘ射线衍射分析表明，零价铜是催化活性中心．差热分析表明，ＺｒＯ２的加入缓和了Ｃｕ（ＮＯ３）２的热分解过程．程序升温还原实验表明，加入ＺｒＯ２后，降低了ＣｕＯ的还原温度．根据上述实验结果，解释了ＺｒＯ２的助催化作用．     

氢化物发生-原子荧光光谱法同时测定环境水中的砷和汞的研究

本文研究了用氢化物发生。原子荧光光谱法同时测定环境水中砷和汞.本法是在盐酸介质中,以硼氢化钾作还原剂,将待测元素转化为挥发性氢化物,以高纯氩气作为载气将挥发性氢化物从溶液中分离,并导入石英炉原子化器中原子化．以高效空心阴极灯作激发光源,被测元素原子受激发后发出原子荧光,荧光强度在一定范围内与被测元素的浓度成正比．讨论并确定了试验的最佳测定条件,方法的检出限：As为0．018μg／L,Hg为0．006μg／L,对As、Hg混合标准溶液（As：5ppb,Hg：0．5ppb）连续测定11次,相对标准偏差：As为2．4％,Hg为10％．并对不同来源的水样进行了分析,回收率为95％～110％．结果表明,该方法操作简便、灵敏度高、干扰少．     

用流动注射氢化物原子吸收法测定土壤中的砷和沉积物中的汞

在选择了样品最佳消化方法、 砷化氢和汞蒸气生成及检测最佳条件的基础上, 将流动注射与氢化物原子吸收光谱法相结合, 建立了土壤中砷和沉积物中汞质量浓度的测定方法. 结果表明, 流动注射氢化物原子吸收法测定土壤中砷的检出限为2 ng/L, 精密度为1.36%~5.08%, 准确度为93.6%~106.1%. 测定沉积物中汞的检出限为3 ng/L, 精密度为0.97%~5.53%, 准确度为93.2%~109.6%. 流动注射氢化物原子吸收法简便、 快速, 分析精密度和准确度均满足环境样品的分析测试要求, 可以用于土壤中砷和沉积物中汞的测定.     

High plastic Zr-Cu-Fe-Al-Nb bulk metallic glasses for biomedical applications

Four Zr-Cu-Fe-Al-based bulk metallic glasses (BMGs) with Zr contents greater than 65at% and minor additions of Nb were designed and prepared. The glass forming abilities, thermal stabilities, mechanical properties, and corrosion resistance properties of the prepared BMGs were investigated. These BMGs exhibit moderate glass forming abilities along with superior fracture and yield strengths compared to previously reported Zr-Cu-Fe-Al BMGs. Specifically, the addition of Nb into this quaternary system remarkably increases the plastic strain to 27.5%, which is related to the high Poisson's ratio and low Young's and shear moduli. The Nb-bearing BMGs also exhibit a lower corrosion current density by about one order of magnitude and a wider passive region than 316L steel in phosphate buffer solution (PBS, pH 7.4). The combination of the optimized composition with high deformation ability, low Young's modulus, and excellent corrosion resistance properties indicates that this kind of BMG is promising for biomedical applications.     

High temperature electrochemical discharge performance of LaFeO3 coated with C/Ni as anode material for NiMH batteries

Perovskite LaFeO₃ is considered as a promising new anode material for nickel/metal hydride batteries due to its low cost, environmental friendliness and high temperature resistance. However, the poor conductivity of LaFeO₃ material restricts the discharge ability, which is problematic for its future widespread application. To solve the above issue, in this study, we prepared C/Ni-coated LaFeO₃ composite in view of the excellent electrical conductivity of carbon and nickel metal. Results show that the C/Ni-coated LaFeO₃ composite delivers remarkably increased discharge capacity of ～345 mAh g^?1 at 60 ?°C in contrast to ～267 mAh g^?1 for pure LaFeO₃. Furthermore, the carbon and nickel not only increase the electrical conductivity of the LaFeO₃ but also reduces the agglomeration of the LaFeO₃, therefore, the C/Ni-coated LaFeO₃ composite serves superior long cycle-life, which maintains 60.9% after 100 cycles (52.9% for the LaFeO₃ sample). In overall, the electrochemical behavior of the C/Ni-coated LaFeO₃ composite confirms its high potential as nickel/metal hydride batteries for energy storage applications.